BugTraceAI CLI 4.0.21-beta

The installation wizard now separates two decisions with short explanations:

• Step 1 selects the terminal TUI, API/MCP backend or both. It clarifies that
  the WEB app is installed separately.
• Step 2 selects local Python or Docker. It explains where dependencies are
  installed and that a Docker TUI still appears in your terminal.
• A readable summary shows the selected interfaces and execution method before
  installation and in the completion instructions.

Option numbers, command-line flags, dependency selection and saved profiles
are unchanged. README and INSTALLATION explain the same choices. All text
is English. The existing Docker bootstrap and immediate TUI launch fixes are
retained.

Validation: 41 installer/profile/completion tests passed, including all six
interactive interface/runtime combinations. Shell syntax and whitespace
checks passed. The menu and summary were inspected without installing
packages or starting scans.

To see the questions again in an existing checkout:

git pull --ff-only
./install.sh

Use ./install.sh --reuse to update or repair using the saved selection;
that command skips the interface and execution questions.